Ok, let me see if I can help
Sound is caused by vibrations. These can pass through a solid, liquid, and gas. But not through vacuum because there are no particles
Answer:

Explanation:
From the question we are told that:
Mass of pulley 
Radius 
Mass of block A 
Mass of block B 
Spring constant
Generally the equation for Torque is mathematically given by
Since 
At mass A

At mass B

At Pulley


Therefore the equation for total force F
At mass A+At mass B+At Pulley




Since From above equation

Therefore



Generally the equation for frequency is mathematically given by


Answer:
0.099C
Explanation:
First, we need to get the common potential voltage using the formula

Where V is the common voltage, C and V represent capacitance and charge respectively. Subscripts 1 and 2 to represent the the first and second respectively. Substituting the above with the following given values then

Therefore

Charge, Q is given by CV hence for the first capacitor charge will be 
Here, 
As you said, the speed is constant in a vacuum, so the speed does not change, The frequency, on the other hand, decreases by half. The wavelength, λ (lambda), the frequency, v, and the speed of light, c, are related by the equation λν = c. We can see that frequency and wavelength are inversely proportional, so an increase in wavelength has a corresponding decrease in frequency.